Reasons for bearing overheating
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Let’s discuss this: if there is a centrifugal pump whose shaft runout is within acceptable limits, the gap between the gland parts is proper, the coupling is properly aligned, and the gap at the impeller’s inlet ring is also within normal ranges, yet during operation the temperature of the bearing housing is high while everything else is normal – including the sound of the bearings and their vibration levels – then how many reasons do you think could cause the bearings to overheat? ;P
Dirty lubricant, excessive or insufficient lubricant, unbalanced rotor
1. Inadequate lubrication, 2. The bearing’s outer ring is moving (something I’ve encountered personally). The issue of dynamic balance mentioned by the person above can cause the vibration levels to be too high
Decrease in lubricant viscosity or contamination with impurities； Abnormal rotation condition of the bearing ；
Check whether the lubricant used is appropriate, if there are any issues with the lubrication method, whether the bearing type is correct, and whether the pump and operating medium meet the design specifications
The fit dimensions of the bearings should be checked; too tight a fit between the inner and outer rings of the bearings and the shaft or housing can lead to high temperatures! Pumps can also experience this situation when the axial force balance is disrupted due to hydraulic reasons. Please pay attention to these two situations. Hope this helps!
The oil quality is poor or water has entered the exhaust port; the bearings and shafts, as well as the bearings and bearing housings, do not have an interference fit.
Why do water pump bearings get hot? ! The main reason is that the bearing has accumulated stress. 1. Excessive force; insufficient concentricity of the coupling and housing, as well as poor balance of radial forces on the impeller. 1. The axial force balance of the impeller is poor due to inadequate hydraulic design or processing! 3. The interference fit of the bearing has an excessive or insufficient amount of interference! Please point out any shortcomings!
1. The lubricating oil has deteriorated or the appropriate grade of oil is not being used. 2. The axial thrust has increased
May I ask what medium is being transported by your centrifugal pump? Was water used during the testing? Could a change in the process medium cause this situation? Also, I would like to ask: you mentioned that the bearing temperature is high. Are there any relevant standards for determining the bearing temperature?